I think this is a futile discussion. I think originality certainly exists, and I've seen it may times in the art world.
I could be wrong, but you seem to imply originality is a made up concept?
Do original thoughts even exist?
Are our comments original or just regurgitation?
Do you believe nothing ever created throughout history is original then?
If you believe originality does exist, where and how do you draw the line?
I don't think people are as boring as you think they are. Or maybe you just don't appreciate art. I can't tell. Some people say they do, but they really don't.
And further, even if we do ignore originality as a concept and pretend for the sake of the argument it doesn't exist, someone still values that style or approach to creation. That probably makes a living based on the subjective value it brings to the table. They sold their work. An AI company now profits off of their work, having used it in an algorithm, without paying anything to those artists.
As an experiment: Give me an example of something you've made yourself that you valued enough to sell, and then tell me why I deserve to have it for free. Maybe that will help me understand. Maybe you can work for me for free?
If none of their work was original or valuable, why even train on it, and why can you even ask for "in style of X"?
Also, the approach of waving responsibility onto individuals is too naïve. If that worked, we'd not need laws or any type of regulation.
Anyway, even with this diatribe I still don't think AI is a bad thing or that it will replace people or or their work—in its current iteration at least. It'll probably improve it, but I certainly understand why people feel violated.